Background: The MacMillans are one of the oldest clans in Scotland, being descended from a 12th century monk or lay priest called Gilchrist; a son of Cormac bishop of Dunkeld, whose great-great-grandfather was the Scots king Macbeth.

The collective name of his descendants, the Clann an Mhaoil or “Children of the Tonsured One” comes from the Gaelic nickname that Gilchrist bore: Maolan, “The (little) Tonsured-One” or An Gillemaol, “The Tonsured Servant (of God)”.

The two resulting surnames, MacMhaolain and MacGhillemhaoil, have been transcribed phonetically by Scots and English speaking people in over 190 different ways over the centuries; so there is no “correct” English version, though the majority of modern clan members use variations on the three most usual forms: Macmillan, MacMillan, McMillan.

In addition to the Knap line, there were two other branches of the clan with their own chieftains: those in Galloway, headed by the McMillans of Brockloch and of the Holm of Dalquhairn, who probably branched off the main line sometime in the fourteenth century; and those in Lochaber, whose chieftains, the Macmillans of Murlagan, branched off from the Knapdale line sometime in the sixteenth century. Each of the main branches spawned others in neighbouring areas; such as Arran (from Knapdale); Ulster (from Galloway); Glen Urquhart & the Outer Hebrides (from Lochaber).